A mathematician couple was having a Frappuccino in Starbucks sitting opposite to each other. Suddenly the guy noticed the text written on the paper in front of them and exclaimed that it was wrong. The girl denied it and said it is appropriate. Both are correct. What is written on the paper?

What is the coolest letter in the alphabet?

How many cubic feet of dirt are in a hole of one foot deep, three feet long, and two feet wide?

A finger goes in me. You fiddle with me when you're bored. The best man always has me first. What am I?

What occurs twice in a week, once in a year but never in a day?

A man who was outside in the rain without an umbrella or hat didn’t get a single hair on his head wet. Why?

What you cannot hold but it is yours?

One night, a man runs away from home. He turns left and keeps running. After some time he turns left again and keeps running. Later, he turns left one more time and runs back home—but when he gets home, he finds a man in a mask. Who was the man in the mask?

What is the centre of gravity?

I cry without having a voice.
I fly without having wings.
I bite without having teeth.
I whisper without a mouth.

Who am I?